N-type tetragonal phase Mo:BiVO4 thin film with hydrogen production activity

Tetragonal BiVO 4 nanorod array exhibits excellent carrier transport properties, but due to its p-type conductivity, it can only be used as a photocathode. In this study, an n-type tetragonal BiVO 4 nanorod array doped with molybdenum was successfully fabricated on fluorine-doped tin oxide (FTO) glass substrates via the hydrothermal method. The doping of Mo and its corresponding concentration were accurately ascertained through X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma (ICP) techniques. Computational simulations revealed that Mo doping induces a shallow donor level beneath the conduction band of BiVO 4 . Notably, the structure and morphology of BiVO 4 did not undergo significant changes after Mo doping, but the conductivity type and conductivity of the surface samples were greatly improved as evidenced by Mott-Schottky and conductive atomic force microscopy (C-AFM) measurements. Impressively, the onset potential for oxygen production when utilized as a photoanode was merely 0.2 V vs RHE. More importantly, although its conduction band position is slightly lower than the hydrogen production potential, the doped sample still demonstrated outstanding activity in water splitting for hydrogen generation.